metamorphic
River Pebble (Quartzite/Chert)
Quartzite with inclusions (SiO2)
Hardness: 7 (Mohs scale), Color: Creamy white with tan/grey patterns, Luster: Waxy to vitreous when wet/polished, Structure: Microcrystalline, Cleavage: None/Conchoidal fracture
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale), Color: Creamy white with tan/grey patterns, Luster: Waxy to vitreous when wet/polished, Structure: Microcrystalline, Cleavage: None/Conchoidal fracture
Formation & geological history
Formed from the metamorphism of quartz-rich sandstone or through silica precipitation. Smooth shape is the result of mechanical weathering in an aquatic environment over years or decades.
Uses & applications
Landscape decoration, aquarium gravel, tumbling for hobbyists, and industrial abrasive.
Geological facts
The rounded shape is caused by saltation, where the rock bounces along a riverbed, grinding its edges down. These are among the most common geological finds worldwide.
Field identification & locations
Identify by its hardness (will scratch glass), smooth surface, and lack of visible individual grains. Found in riverbeds, glacial deposits, and beaches.
More like this
